Suprascapular nerve blockage for painful shoulder pathology - a systematic review and meta-analysis of treatment techniques

BACKGROUND

Suprascapular nerve blockade (SSNB) through injection (SSNBi) and/or pulsed radiofrequency (PRF) provide options for the management of painful shoulder pathology. Multiple techniques for delivery of SSNB are described but no consensus on optimal symptom control is available. This systematic review and meta-analysis aims to assess patient-focussed outcomes in SSNB and explore the impact of variation in the technical application of this treatment modality.

METHODS

MEDLINE, Embase and CINAHL were searched for case series, cohort studies and randomised control trials published from database inception until 28 January 2021. Articles reporting use of SSNBi or PRF for treatment of shoulder pain with a minimum 3 months follow-up were included. Patient-reported outcome measures (PROMs) were extracted and the pooled standardised mean difference (SMD), weighted by study size, was reported. Quality of methodology was assessed using Wylde's nonsummative four-point system.

FINDINGS

Of 758 references, 18 studies were included, totalling 704 SSNB. Average pain improvement at 3 months was 52.3%, with meta-analysis demonstrating a SMD of 2.37. Whereas SSNBi combined with PRF shows the greatest SMD of 2.75, this did not differ significantly from SSNBi or PRF when used as monotherapy. Location of treatment and the guidance technique used did not influence outcome.

CONCLUSION

SSNBi and PRF provide safe and effective treatment for shoulder pain, as judged by PROMs. This may be of particular value in aging or comorbid patients and with surgical restrictions during the COVID-19 pandemic. Regardless of technique, patients experience a marked improvement in pain that is maintained beyond 3 months.

Baseline bone turnover marker levels can predict change in bone mineral density during antiresorptive treatment in osteoporotic patients: the Copenhagen bone turnover marker study

Anti-resorptive osteoporosis treatment might be more effective in patients with high bone turnover. In this registry study including clinical data, high pre-treatment bone turnover measured with biochemical markers was correlated with higher bone mineral density increases. Bone turnover markers may be useful tools to identify patients benefitting most from anti-resorptive treatment.

INTRODUCTION

In randomized, controlled trials of bisphosphonates, high pre-treatment levels of bone turnover markers (BTM) were associated with a larger increase in bone mineral density (BMD). The purpose of this study was to examine this correlation in a real-world setting.

METHODS

In this registry-based cohort study of osteoporosis patients (n = 158) receiving antiresorptive therapy, the association between pre-treatment levels of plasma C-telopeptide of type I Collagen (CTX) and/or N-terminal propeptide of type I procollagen (PINP) and change in bone mineral density (BMD) at lumbar spine, total hip, and femoral neck upon treatment was examined. Patients were grouped according to their pre-treatment BTM levels, defined as values above and below the geometric mean for premenopausal women.

RESULTS

Pre-treatment CTX correlated with annual increase in total hip BMD, where patients with CTX above the geometric mean experienced a larger annual increase in BMD (p = 0.008) than patients with CTX below the geometric mean. The numerical pre-treatment level of CTX showed a similar correlation at all three skeletal sites (total hip (p = 0.03), femoral neck (p = 0.04), and lumbar spine (p = 0.0003)). A similar association was found for PINP where pre-treatment levels of PINP above the geometric mean correlated with a larger annual increase in BMD for total hip (p = 0.02) and lumbar spine (p = 0.006).

CONCLUSION

Measurement of pre-treatment BTM levels predicts osteoporosis patients' response to antiresorptive treatment. Patients with high pre-treatment levels of CTX and/or PINP benefit more from antiresorptive treatment with larger increases in BMD than patients with lower pre-treatment levels.

A digital holography ex situ measurement characterization of plasma-exposed surface erosion from an electrothermal arc source

Digital holography has been proposed to fulfill a need for an imaging diagnostic capable of in situ monitoring of surface erosion caused by plasma-material interaction in nuclear fusion devices. A digital holography diagnostic for 3D surface erosion measurement has been developed at Oak Ridge National Laboratory with the goal of deployment on a plasma device. A proof-of-concept in situ demonstration is planned which would involve measurement of plasma erosion on targets exposed to an electrothermal arc source. This work presents the results of an ex situ characterization of the capability and limitations of holographic imaging of targets exposed to the arc source. Targets were designed to provide a fiducial for comparison of deformed and unaffected areas. The results indicated that the average net erosion was ∼150 nm/plasma exposure, which is expected to be within the diagnostic's measurement capacity. Surface roughness averages determined by holographic image analysis showed good agreement with measurements taken with a profilometer. The limit of the holography diagnostic's x-y spatial resolution was characterized by comparison with scanning electron microscope imaging.

Measurements of dynamic surface changes by digital holography for in situ plasma erosion applications

There are currently few viable diagnostic techniques for in situ measurement of plasma facing component erosion. Digital holography is intended to fill this gap. Progress on the development of single and dual CO₂ laser digital holography diagnostics for in situ plasma facing component erosion is discussed. The dual laser mode's synthetic wavelength allows the measurable range to be expanded by a factor of ∼400 compared to single laser digital holography. This allows the diagnostic to measure surface height changes of up to 4.5 μm in single laser mode and up to 2 mm in dual laser mode. Results include ex situ measurements of plasma eroded targets and also dynamic measurements of nm and μm scale motion of a target mounted on a precision translation stage. Dynamic measurements have successfully been made with the system operating in both single and dual laser modes, from ∼50 nm to ∼4 μm in single laser mode and up to ∼400 μm in dual laser mode (limited only by the stage speed and camera acquisition duration). These results demonstrate the feasibility of using digital holography to characterize plasma facing component erosion dynamically, i.e., during plasma exposure. Results of proof-of-principle in situ digital holographic measurements of targets exposed to an electrothermal arc plasma source are presented.

Assessing Patient-Centred Outcomes in Lateral Elbow Tendinopathy: A Systematic Review and Standardised Comparison of English Language Clinical Rating Systems

Background

Lateral elbow tendinopathy (LET) is a common condition affecting adults. Although a lack of treatment consensus continues to prompt numerous effectiveness studies, there is a paucity of clear guidance on the choice of outcome measure. Our aim was to undertake a standardised evaluation of the available clinical rating systems that report patient-centred outcomes in LET.

Methods

A systematic review of studies reporting the development, assessment of metric properties and/or use of instruments aiming to quantify LET-specific patient-centred outcome measures was conducted in MEDLINE, Embase and CINAHL (inception-2017) adhering to PRISMA guidance. The evidence for each instrument was independently assessed by two reviewers using the standardised evaluating measures of patient-reported outcomes (EMPRO) method evaluating overall and attribute-specific instrument performance (metric properties and usability). EMPRO scores > 50/100 were considered indicative of high performance.

Results

Out of 7261 references, we identified 105 articles reporting on 15 instruments for EMPRO analysis. Median performance score was 41.6 (range 21.6–72.5), with four instruments meeting high-performance criteria: quick Disabilities of the Arm Shoulder and Hand score (qDASH) (72.5), DASH (66.9), Oxford Elbow Score (OES) (66.6) and Patient-Rated Tennis Elbow Evaluation (PRTEE) (57.0). One hundred seventy-nine articles reported instrument use internationally with DASH as the most frequent (29.7% articles) followed by PRTEE (25.6%), MEPS (15.1%) and qDASH (8.1%). The correlation between frequency of use and performance was r = 0.35 (95%CI − 0.11; 0.83).

Conclusions

This is the first study to provide standardised guidance on the choice of measures for LET. A large number of clinical rating systems are both available and being used for patients with LETs. Robust evidence is available for four measures, the DASH, QDASH, PRTEE and OES. The use of instruments in the literature is only in part explained by instrument performance.

Electronic supplementary material

The online version of this article (10.1186/s40798-019-0183-2) contains supplementary material, which is available to authorized users.

Peeking into the Black Box of Coregistration in Clinical fMRI: Which Registration Methods Are Used and How Well Do They Perform?

BACKGROUND AND PURPOSE

Interpretation of fMRI depends on accurate functional-to-structural alignment. This study explores registration methods used by FDA-approved software for clinical fMRI and aims to answer the following question: What is the degree of misalignment when registration is not performed, and how well do current registration methods perform?

MATERIALS AND METHODS

This retrospective study of presurgical fMRI for brain tumors compares nonregistered images and 5 registration cost functions: Hellinger, mutual information, normalized mutual information, correlation ratio, and local Pearson correlation. To adjudicate the accuracy of coregistration, we edge-enhanced echo-planar maps and rated them for alignment with structural anatomy. Lesion-to-activation distances were measured to evaluate the effects of different cost functions.

RESULTS

Transformation parameters were congruent among Hellinger, mutual information, normalized mutual information, and the correlation ratio but divergent from the local Pearson correlation. Edge-enhanced images validated the local Pearson correlation as the most accurate. Hellinger worsened misalignment in 59% of cases, primarily exaggerating the inferior translation; no cases were worsened by the local Pearson correlation. Three hundred twenty lesion-to-activation distances from 25 patients were analyzed among nonregistered images, Hellinger, and the local Pearson correlation. ANOVA analysis revealed significant differences in the coronal (P < .001) and sagittal (P = .04) planes. If registration is not performed, 8% of cases may have a >3-mm discrepancy and up to a 5.6-mm lesion-to-activation distance difference. If a poor registration method is used, 23% of cases may have a >3-mm discrepancy and up to a 6.9-mm difference.

CONCLUSIONS

The local Pearson correlation is a special-purpose cost function specifically designed for T2*-T1 coregistration and should be more widely incorporated into software tools as a better method for coregistration in clinical fMRI.

Clinical and radiologic outcomes following total shoulder arthroplasty using Arthrex Eclipse stemless humeral component with minimum 2 years' follow-up

BACKGROUND

Stemless humeral components benefit from less morbidity, better reproduction of the humeral anatomy, ease of revision, and fewer stem-related complications. Encouraging results are available up to 9 years after surgery from the designer's series. This is an independent study of 100 consecutive Eclipse stemless prostheses for osteoarthritis with a minimum 2-year follow-up (range, 2-6 years).

METHODS

We included only total shoulder arthroplasties performed for osteoarthritis. The primary outcome was the Oxford Shoulder Score (OSS) after 2 years. Secondary outcome measures were change in shoulder range of movement and radiographic analysis of prosthesis size and position.

RESULTS

The mean OSS at 2 years was 38 of 48, with a mean improvement of +19 points (range, +17 to +22 points; P < .001). There was no significant deterioration in OSS after 3 or 4 years' follow-up. Statistically significant improvement was seen in arm elevation and external rotation (P < .001). There were 5 reoperations-1 for impingement of the biceps stump and 4 revisions to reverse arthroplasty for cuff failure. Of the prostheses, 92% were sized within 2 mm of the anatomic head size, and in 76% of prostheses, the center of rotation was within 3 mm of the native anatomy. An incomplete radiolucent line was present in zone B (around the cage screw) in a single patient at 2 years following surgery. There were no cases of loosening or infection.

CONCLUSION

The functional and radiographic outcomes of Eclipse total shoulder replacement are excellent. We were able to accurately reproduce the native anatomy in the majority of cases, with no implant loosening, at 2 to 6 years' follow-up.

Dual laser holography for in situ measurement of plasma facing component erosion (invited)

A digital holography (DH) surface erosion/deposition diagnostic is being developed for 3D imaging of plasma facing component surfaces in situ and in real time. Digital holography is a technique that utilizes lasers reflected from a material surface to form an interferogram, which carries information about the topology of the surface when reconstructed. As described in this paper, dual CO₂ lasers at 9.271 and 9.250 μm wavelengths illuminate the interrogated surface (at a distance of ∼1 m) in a region of ∼1 cm × 1 cm. The surface feature resolution is ∼0.1 mm in the plane of the surface, and the depth resolution ranges from ∼0.0001 to ∼2 mm perpendicular to the surface. The depth resolution lower limit is set by single-laser and detector optical limitations, while the upper limit is determined by 2π phase ambiguity of the dual-laser synthetic wavelength. Measurements have been made "on the bench" to characterize the single-laser and dual-laser DH configurations utilizing standard resolution targets and material targets that were previously exposed to high flux plasmas in either the Prototype Material Plasma Exposure eXperiment (Proto-MPEX) or the electro-thermal (ET) arc source. Typical DH measurements were made with 0.03 ms integration with an IR camera that can be framed at rates approaching 1.5 kHz. The DH diagnostic system is progressing toward in situ measurements of plasma erosion/deposition either on Proto-MPEX or the ET arc source.

Triceps on, alignment off? A comparison of total elbow arthroplasty component positioning with a triceps-on and a triceps-off approach

Introduction This retrospective review investigates whether the triceps-on approach obtains alignment of total elbow arthroplasty implants equivalent to a triceps-off approach. Methods The last 30 consecutive total elbow arthroplasties performed by the senior author were reviewed to identify the approach used and pathology treated. Initially, a triceps split and reflection approach was used, then a triceps-preserving approach. Two blinded reviewers measured the component alignment in standardised radiographs. Pearson's correlation coefficient was calculated to investigate inter/intra-observer and error. The two groups were compared using an unpaired Student t-test. Results There were 13 elbows in the triceps-off group and 17 in the triceps-on group. Pearson's coefficient was 0.75 for interobserver error, 0.89 for intra-observer error. There was no statistical difference between the achieved alignment. All ulna components were flexed with a mean angle deviation of 4.5 degrees in the triceps-off group and 5.7 degrees in the triceps on. Two (15%) ulna components in the triceps-off group were placed in over 5 degrees of flexion, compared with seven (44%) in the triceps-on group. Conclusion These results demonstrate no statistical difference in the achieved alignment between the two groups. Surgeons should beware of the tendency to place the ulna component in a flexed position, especially in the triceps-on approach.

The spread of Injectate after ultrasound-guided lateral elbow injection - a cadaveric study

Background

Injections into the tendinous portion of the common extensor origin are a common intervention in the treatment of Lateral Elbow Tendinopathy (LET). Clinical trials report a heterogeneous selection of injectate volumes and delivery techniques, with systematic reviews finding no clear consensus. The aim of this study was to assess the intratendinous distribution and surrounding tissue contamination of ultrasound-guided injections into the Common Extensor Tendon (CET) of the elbow.

Methods

Twenty cadaveric elbows were injected by a Consultant Radiologist under Ultrasound guidance. Elbows were randomised to equal groups of 1 or 3 mls of methylene blue injection, delivered using single shot or fenestrated techniques. Following injection, each cadaver underwent a dry arthroscopy and dissection of superficial tissues. The CET was excised, set and divided into 1 mm sections using microtome. Each slice was photographed and analysed to assess spread and pixel density of injectate in four colour graduations. The cross-sectional area of distribution was calculated and compared between groups.

Results

In all 20 cadaveric samples, contamination of the joint was noted on arthroscopy and dissection. Injectate spread through over 97% of the cross-sectional area. No differences were found in intratendinous spread of injectate between differing volumes or techniques.

Conclusion

This study found that commonly used injection volumes and techniques distribute widely throughout cadaveric CETs. There was no improvement when the volume was increased from 1 to 3 mls or between single shot of fenestrated injection techniques. It should be noted that joint contamination using these techniques and volumes may be inevitable.

Electronic supplementary material

The online version of this article (10.1186/s40634-018-0142-8) contains supplementary material, which is available to authorized users.

Comparative learning curves for early complications in anatomical and reverse shoulder arthroplasty

Introduction There has been a significant increase in the implantation of reverse shoulder replacements over anatomical shoulder replacements in the past five years. Few comparative data exist comparing early complication rates and learning curves. This study aimed to evaluate the early complication rates and learning curves of a single surgeon series of anatomical and reverse shoulder replacements over the first five years of independent practice. Materials and methods The first 100 anatomical and 100 reverse shoulder replacements performed between July 2011 and July 2016 were reviewed to identify early complications. Cumulative sum plots were used to analyse the learning-curve effect. Results Early complications were noted in 4 anatomical and 17 reverse shoulder replacements. One of the anatomical and ten of the reverse shoulder replacements required a return to theatre within three months. The early complication rates were observed to be significantly higher in the reverse shoulder replacement group compared with the anatomical shoulder replacement group (odds ratio 4.9; 95% confidence interval 1.6-15.2, P 1/4 0.057). An inflection point on the anatomical shoulder replacement cumulative sum plot suggestive of a trend to consistent performance was reached at 16 cases. No inflection point was observed on the reverse shoulder replacement cohort. Conclusions We observed a significantly higher early complication rate within the reverse shoulder replacement cohort, with a tenfold increase in early reoperations. In comparison to the trend seen after 16 cases for anatomical shoulder replacement, no trend was seen in the reverse shoulder replacement cohort. This either reflects the higher complication rate seen in reverse shoulder replacement or that the learning curve extends beyond 100 cases, highlighting the need for extended performance monitoring.

Clinical rating systems in elbow research-a systematic review exploring trends and distributions of use

BACKGROUND

Clinical rating systems are used as outcome measures in clinical trials and attempt to gauge the patient's view of his or her own health. The choice of clinical rating system should be supported by its performance against established quality standards.

METHODS

A search strategy was developed to identify all studies that reported the use of clinical rating systems in the elbow literature. The strategy was run from inception in Medline Embase and CINHAL. Data extraction identified the date of publication, country of data collection, pathology assessed, and the outcome measure used.

RESULTS

We identified 980 studies that reported clinical rating system use. Seventy-two separate rating systems were identified. Forty-one percent of studies used ≥2 separate measures. Overall, 54% of studies used the Mayo Elbow Performance Score (MEPS). For arthroplasty, 82% used MEPS, 17% used Disabilities of Arm, Shoulder and Hand (DASH), and 7% used QuickDASH. For trauma, 66.7% used MEPS, 32% used DASH, and 23% used the Morrey Score. For tendinopathy, 31% used DASH, 23% used Patient-Rated Tennis Elbow Evaluation (PRTEE), and 13% used MEPS. Over time, there was an increased proportional use of the MEPS, DASH, QuickDASH, PRTEE, and the Oxford Elbow Score.

CONCLUSIONS

This study identified a wide choice and usage of clinical rating systems in the elbow literature. Numerous studies reported measures without a history of either a specific pathology or cross-cultural validation. Interpretability and comparison of outcomes is dependent on the unification of outcome measure choice. This was not demonstrated currently.

The colonisation of the glenohumeral joint by Propionibacterium acnes is not associated with frozen shoulder but is more likely to occur after an injection into the joint

AIMS

Our aim was to investigate the prevalence of Propionibacterium (P.) acnes in the subcutaneous fat and capsule of patients undergoing shoulder surgery for frozen shoulder or instability.

PATIENTS AND METHODS

A total of 46 patients undergoing either an arthroscopic capsular release or stabilisation had biopsies taken from the subcutaneous fat and capsule of the shoulder at the time of surgery. These samples were sent for culture in enrichment, and also for Nucleic Acid Amplification testing. The prevalence of P. acnes and other microbes was recorded. Fisher's exact test of binary variables was used to calculate the association with significance set at p < 0.05. Assessment of influence of independent variables including a pre-operative glenohumeral injection, fat colonisation and gender, was undertaken using binary linear regression.

RESULTS

A total of 25 patients (53%) had P. acnes in one or more tissue samples and 35 (74%) had other bacterial species. The same microbe was found in the subcutaneous fat and the capsule in 13 patients (28%). There was no statistically significant association between the surgical pathology and capsular colonisation with P. acnes (p = 0.18) or mixed identified bacterial species (p = 0.77). Male gender was significantly associated with an increased capsular colonisation of P. acnes (odds ratio (OR) 12.38, 95% confidence interval (CI) 1.43 to 106.77, p = 0.02). A pre-operative glenohumeral injection was significantly associated with capsular P. acnes colonisation (OR 5.63, 95% CI 1.07 to 29.61, p = 0.04. Positive fat colonisation with P. acnes was significantly associated with capsular P. acnes (OR 363, 95% CI 20.90 to 6304.19, p < 0.01). Regression models pseudo R² found fat colonisation with P. acnes to explain 70% of the variance of the model. Patients who had a pre-operative glenohumeral injection who were found intra-operatively to have fat colonisation with P. acnes had a statistically significant association with colonisation of their capsule with P. acnes (OR 165, 95% CI 13.51 to 2015.24, p < 0.01).

CONCLUSION

These results show a statistically significant association between subcutaneous skin P. acnes culture and P. acnes capsular culture, especially when the patient has undergone a previous injection. The results refute the hypothesis that P. acnes causes frozen shoulder. Cite this article: Bone Joint J 2017;99-B:1067-72.

Triceps on approach for total elbow arthroplasty: worth preserving? A review of approaches for total elbow arthroplasty

Total elbow arthroplasty can be a rewarding operation and is becoming increasingly used in the elderly fracture population. Multiple approaches are represented in the literature and deciding on the best approach is difficult. This review discusses approaches and their reported outcomes, aiming to allow surgeons to make an informed choice about which approach to use.

Anatomy of the terminal branch of the posterior circumflex humeral artery: relevance to the deltopectoral approach to the shoulder

AIMS

Despite the expansion of arthroscopic surgery of the shoulder, the open deltopectoral approach is increasingly used for the fixation of fractures and arthroplasty of the shoulder. The anatomy of the terminal branches of the posterior circumflex humeral artery (PCHA) has not been described before. We undertook an investigation to correct this omission.

PATIENTS AND METHODS

The vascular anatomy encountered during 100 consecutive elective deltopectoral approaches was recorded, and the common variants of the terminal branches of the PCHA are described.

RESULTS

In total, 92 patients (92%) had a terminal branch that crossed the space between the deltoid and the proximal humerus and which was therefore vulnerable to tearing or avulsion during the insertion of the blade of a retractor during the deltopectoral approach to the shoulder. In 75 patients (75%) there was a single vessel, in 16 (16%) a double vessel and in one a triple vessel.

CONCLUSION

The relationship of these vessels to the landmark of the tendon of the insertion of pectoralis major into the proximal humerus is described. Damage to these previously undocumented branches can cause persistent bleeding leading to prolonged surgery and post-operative haematoma and infection, as well as poor visualisation during the procedure. Cite this article: Bone Joint J 2016;98-B:1395-8.

Correction of ischaemic brain acidosis with SQ29,548/1-benzylimidazole

Thromboxane A2 (TXA2) is a proaggregatory vasoconstrictor that is synthesized and released during reperfusion of ischaemic brain. We administered a TXA2 receptor antagonist, SQ29,548, and a thromboxane A synthase inhibitor, 1-benzylimidazole (1-BI), to rats subjected to 30 min of reversible forebrain ischaemia. Cerebral thromboxane B2 (TXB2), the stable metabolite of TXA2, measured after 60 min of reperfusion was 0.37 +/- 0.08 ng/mg brain protein in animals treated with SQ29,548/1-BI compared with 1.20 +/- 0.16 in ischaemic controls (p < 0.05). Cerebral pH determined by 31P magnetic resonance spectroscopy was higher in treated animals, 7.06 +/- 0.04, than in ischaemic controls, 6.5 +/- 0.01, after 20 min of reperfusion (p < or = 0.01). The significant elevation of cerebral pH in treated animals persisted at 30 (7.17 +/- 0.05 vs. 6.5 +/- 0.01; p < or = 0.01), 35 (7.17 +/- 0.05 vs. 6.44 +/- 0.04; p < or = 0.01), and 40 min of reperfusion (7.06 +/- 0.06 vs. 6.37 +/- 0.01; p < or = 0.05). We conclude that SQ29,548/1-BI reduces thromboxane levels and promotes resolution of tissue acidosis in ischaemic brain. The combination of a TXA2 receptor antagonist with a thromboxane A synthase inhibitor deserves further study as a potential treatment for acute cerebral infarction.

Association between Propionibacterium acnes and frozen shoulder: a pilot study

BACKGROUND

Frozen shoulder has not previously been shown to be associated with infection. The present study set out to confirm the null hypothesis that there is no relationship between infection and frozen shoulder using two modern scientific methods, extended culture and polymerase chain reaction (PCR) for bacterial nucleic acids.

METHODS

A prospective cohort of 10 patients undergoing arthroscopic release for stage II idiopathic frozen shoulder had two biopsies of tissue taken from the affected shoulder joint capsule at the time of surgery, along with control biopsies of subdermal fat. The biopsies and controls were examined with extended culture and PCR for microbial nucleic acid.

RESULTS

Eight of the 10 patients had positive findings on extended culture in their shoulder capsule and, in six of these, Propionibacterium acnes was present.

CONCLUSIONS

The findings mean that we must reject the null hypothesis that there is no relationship between infection and frozen shoulder. More studies are urgently needed to confirm or refute these findings. If they are confirmed, this could potentially lead to new and effective treatments for this common, painful and disabling condition. Could P. acnes be the Helicobacter of frozen shoulder?

Arthroscopic capsular release for idiopathic frozen shoulder with intra-articular injection and a controlled manipulation

INTRODUCTION

The aim of this prospective study was to assess the immediate and long-term effectiveness of arthroscopic capsular release in a large cohort of patients with a precise and isolated diagnosis of stage II idiopathic frozen shoulder.

METHODS

All patients underwent a preoperative evaluation. Patients with secondary frozen shoulder and those with concurrent pathology at arthroscopy were excluded. This left 136 patients with a stage II arthroscopically confirmed idiopathic frozen shoulder. At each postoperative attendance, a record was made of pain, function and range of motion. At 12 months, the Oxford shoulder score was calculated, and pain and range of motion were assessed.

RESULTS

Fifty per cent achieved good pain relief within a week and eighty per cent within six weeks of arthroscopic capsular release. The mean preoperative visual analogue scale pain score was 6.6 and the mean postoperative score was 1.0. The mean time to achieving good pain relief was 16 days following surgery. No patient could sleep through the night prior to surgery while 90% reported having a complete night's sleep at a mean of 12 days after surgery. The mean postoperative Oxford shoulder score was 38/48 and the mean improvement was 19.2.

CONCLUSIONS

This large series demonstrates that arthroscopic capsular release is a safe procedure, with rapid improvement in pain and a marked improvement in range of motion.

Novel carvedilol analogues that suppress store-overload-induced Ca2+ release

Carvedilol is a uniquely effective drug for the treatment of cardiac arrhythmias in patients with heart failure. This activity is in part because of its ability to inhibit store-overload-induced calcium release (SOICR) through the RyR2 channel. We describe the synthesis, characterization, and bioassay of ca. 100 compounds based on the carvedilol motif to identify features that correlate with and optimize SOICR inhibition. A single-cell bioassay was employed on the basis of the RyR2-R4496C mutant HEK-293 cell line in which calcium release from the endoplasmic reticulum through the defective channel was measured. IC50 values for SOICR inhibition were thus obtained. The compounds investigated contained modifications to the three principal subunits of carvedilol, including the carbazole and catechol moieties, as well as the linker chain containing the β-amino alcohol functionality. The SAR results indicate that significant alterations are tolerated in each of the three subunits.

The frequency of and associations with hospitalization secondary to lupus flares from the 1000 Faces of Lupus Canadian cohort

Objectives

Hospitalization is a major factor in health care costs and a surrogate for worse outcomes in chronic disease. The aim of this study was to determine the frequency of hospitalization secondary to lupus flare, the causes of hospitalization, and to determine risk factors for hospitalization in patients with systemic lupus erythematosus (SLE).

Methods

Data were collected as part of the 1000 Canadian Faces of Lupus, a prospective cohort study, where annual major lupus flares including hospitalizations were recorded over a 3-year period.

Results

Of 665 patients with available hospitalization histories, 68 reported hospitalization related to a SLE flare over 3 years of follow-up. The average annual hospitalization rate was 7.6% (range 6.6–8.9%). The most common reasons for hospitalization were: hematologic (22.1%), serositis (20.6%), musculoskeletal (MSK) (16.2%), and renal (14.7%). Univariate risk factors for lupus hospitalization included (OR [95% CI]; p < 0.05): juvenile-onset lupus (2.2 [1.1–4.7]), number of ACR SLE criteria (1.4 [1.1–1.7], baseline body mass index (BMI) (1.1 [1.0–1.1]), psychosis (3.4 [1.2–9.9]), aboriginal race (3.2 [1.5–6.7]), anti-Smith (2.6 [1.2–5.4]), erythrocyte sedimentation rate >25 mm/hr (1.9 [1.1–3.4]), proteinuria >0.5 g/d (4.2 [1.9–9.3], and SLAM-2 score (1.1 [1.0–1.2]). After multivariate regression only BMI, number of ACR criteria, and psychosis were associated with hospitalization for lupus flare.

Conclusions

The mean annual rate of hospitalization attributed to lupus was lower than expected. Hematologic, serositis, MSK and renal were the most common reasons. In a regression model elevated BMI, more ACR criteria and psychosis were associated with hospitalization.

Social insect genomes exhibit dramatic evolution in gene composition and regulation while preserving regulatory features linked to sociality

Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contains ∼4000 novel genes, but only 64 of these genes are conserved among all seven ants. Many gene families have been expanded in ants, notably those involved in chemical communication (e.g., desaturases and odorant receptors). Alignment of the ant genomes revealed reduced purifying selection compared with Drosophila without significantly reduced synteny. Correspondingly, ant genomes exhibit dramatic divergence of noncoding regulatory elements; however, extant conserved regions are enriched for novel noncoding RNAs and transcription factor–binding sites. Comparison of orthologous gene promoters between eusocial and solitary species revealed significant regulatory evolution in both cis (e.g., Creb) and trans (e.g., fork head) for nearly 2000 genes, many of which exhibit phenotypic plasticity. Our results emphasize that genomic changes can occur remarkably fast in ants, because two recently diverged leaf-cutter ant species exhibit faster accumulation of species-specific genes and greater divergence in regulatory elements compared with other ants or Drosophila. Thus, while the “socio-genomes” of ants and the honeybee are broadly characterized by a pervasive pattern of divergence in gene composition and regulation, they preserve lineage-specific regulatory features linked to eusociality. We propose that changes in gene regulation played a key role in the origins of insect eusociality, whereas changes in gene composition were more relevant for lineage-specific eusocial adaptations.

Genotype-phenotype studies of VCP-associated inclusion body myopathy with Paget disease of bone and/or frontotemporal dementia

Valosin containing protein (VCP) disease associated with inclusion body myopathy, Paget disease of the bone and frontotemporal dementia is a progressive autosomal dominant disorder caused by mutations in Valosin containing protein gene. To establish genotype-phenotype correlations we analyzed clinical and biochemical markers from a database of 190 members in 27 families harboring 10 missense mutations. Individuals were grouped into three categories: symptomatic, presymptomatic carriers and noncarriers. The symptomatic families were further divided into ten groups based on their VCP mutations. There was marked intra and inter-familial variation; and significant genotype-phenotype correlations were difficult to establish because of small numbers. Nevertheless when comparing the two most common mutations, R155C mutation was found to be more severe, with an earlier onset of myopathy and Paget (p = 0.03). Survival analysis of all subjects revealed an average life span after diagnosis of myopathy and Paget of 18 and 19 years respectively, and after dementia only 6 years. R155C had a reduced survival compared to the R155H mutation (p = 0.03).We identified amyotrophic lateral sclerosis (ALS) was diagnosed in 13 individuals (8.9%) and Parkinson's disease in five individuals (3%); however, there was no genotypic correlation. This study represents the largest dataset of patients with VCP disease and expands our understanding of the natural history and provides genotype-phenotype correlations in this unique disease.

Indications for reverse shoulder replacement: a systematic review

The outcome of an anatomical shoulder replacement depends on an intact rotator cuff. In 1981 Grammont designed a novel large-head reverse shoulder replacement for patients with cuff deficiency. Such has been the success of this replacement that it has led to a rapid expansion of the indications. We performed a systematic review of the literature to evaluate the functional outcome of each indication for the reverse shoulder replacement. Secondary outcome measures of range of movement, pain scores and complication rates are also presented.

Direct fed microbial supplementation repartitions host energy to the immune system

Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P < 0.05) was measured in DFMD fed broilers. In contrast, the respiration rate of the thymus in those broilers was increased (P < 0.05). The PBMC from DFMD fed broilers had increased ATP concentrations and exhibited increased ATP turnover (P < 0.01). To determine if the increased energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P < 0.05) and an increase in total IgA (P < 0.05). Collectively, these data indicate that supplementation with the direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.

Carvedilol and its new analogs suppress arrhythmogenic store overload-induced Ca2+ release

Carvedilol is one of the most effective beta blockers for preventing ventricular tachyarrhythmias in heart failure, but the mechanisms underlying its favorable antiarrhythmic benefits remain unclear. Spontaneous Ca(2+) waves, also called store overload-induced Ca(2+) release (SOICR), evoke ventricular tachyarrhythmias in individuals with heart failure. Here we show that carvedilol is the only beta blocker tested that effectively suppresses SOICR by directly reducing the open duration of the cardiac ryanodine receptor (RyR2). This unique anti-SOICR activity of carvedilol, combined with its beta-blocking activity, probably contributes to its favorable antiarrhythmic effect. To enable optimal titration of carvedilol's actions as a beta blocker and as a suppressor of SOICR separately, we developed a new SOICR-inhibiting, minimally beta-blocking carvedilol analog, VK-II-86. VK-II-86 prevented stress-induced ventricular tachyarrhythmias in RyR2-mutant mice and did so more effectively when combined with either of the selective beta blockers metoprolol or bisoprolol. Combining SOICR inhibition with optimal beta blockade has the potential to provide antiarrhythmic therapy that can be tailored to individual patients.

Changing prophylactic antibiotic protocol for reducing Clostridium difficile-associated diarrhoeal infections

PURPOSE

To determine whether a change in prophylactic antibiotic protocol for orthopaedic surgeries may reduce the frequency of Clostridium difficile-associated diarrhoeal infections.

METHODS

Records of 1331 patients who underwent trauma or elective surgeries involving implantation of metalwork were reviewed. 231 trauma and 394 elective patients who received intravenous cefuroxime-based antibiotic prophylaxis between August 2006 and January 2007 were compared with 216 trauma and 490 elective patients who received a single dose of gentamicin and flucloxacillin or teicoplanin for antibiotic prophylaxis between August 2007 and January 2008. Diarrhoeal faecal specimens of 148 (33%) trauma patients and 106 (12%) elective patients were examined. The outcome variables were the rates of C difficile infection and early deep wound infection.

RESULTS

There were 32 cases of C difficile-associated diarrhoeal infection and 28 cases of early deep wound infection. The frequency of C difficile-associated diarrhoeal infection decreased after use of the new antibiotic protocol (from 4 to 1%, p = 0.004), particularly in the trauma patients (from 8 to 3%, p = 0.02); in the elective patients the difference was not significant (from 1 to 0.5%, p = 0.27). The change of antibiotic protocol did not significantly affect the incidence of deep wound infections in the trauma (p = 0.46) or elective (p = 0.90) patients. The rate of C difficile infection was 8-fold higher in the trauma than elective patients, both before and after the change of protocol.

CONCLUSION

Changing antibiotic protocol is one way of reducing the incidence of C difficile-associated diarrhoeal infections in orthopaedic patients, without increasing the rate of deep wound infections.

Another fractured neck of femur: do we need a lateral X-ray?

OBJECTIVE

This study aimed to define the role of the lateral X-ray in the assessment and treatment planning of proximal femoral fractures. Occult fractures were not included.

METHODS

Radiographs from 359 consecutive patients with proximal femoral fractures admitted to our emergency department over a 12 month period were divided into anteroposterior (AP) views and lateral views. Three blinded reviewers independently assessed the radiographs, first AP views alone then AP plus lateral views, noting the fracture classification for each radiograph. These assessments were then compared with the intra-operative diagnosis, which was used as the gold standard. A 2 × 2 contingency square table was created and Pearson's χ(2) test was used for statistical analysis.

RESULTS

The rate of correct classification by the reviewers was improved by the assessment of the lateral X-ray in addition to the AP view for intracapsular fractures (p<0.013) but not for extracapsular fractures (p=0.27). However, the only advantage obtained by assessing the lateral view in intracapsular fractures was the detection of displacement where the fracture appeared undisplaced on the initial AP view.

CONCLUSION

This study provides statistical evidence that one view is adequate and safe for the majority of hip fractures. The lateral radiograph should not be performed routinely in order to make considerable savings in money and time and to avoid unnecessary patient discomfort.

Dynamic and static external fixation for distal radius fractures--a systematic review

INTRODUCTION

External fixation of distal radius fractures may be static (wrist-bridging) or dynamic (wrist-bridging with mobile hinge or non-bridging). The aim of this systematic review is to investigate the effectiveness of different methods of external fixation for unstable distal radius fractures.

METHODS

A Medline database search was performed with strict eligibility criteria to obtain the highest quality evidence from meta-analyses, RCTs and comparative studies. Eligible studies were critically appraised using levels of evidence and RCTs were further appraised using a validated scoring tool.

RESULTS

Fifty-four studies were identified of which eight were included. There were six RCTs and two retrospective comparative studies. Three RCTs compared non-bridging with static wrist-bridging fixation. Two RCTs compared dynamic wrist-bridging with static wrist-bridging fixation. One study compared dynamic wrist-bridging with non-bridging fixation. The RCTs varied in quality and scored between 12 and 23 out of a maximum of 33 points. The evidence suggests that there are no functional or radiological benefits for a dynamic wrist-bridging external fixator with a mobile hinge joint over a static wrist-bridging external fixator. The evidence also suggests that there are no benefits for non-bridging over static wrist-bridging external fixation in older patients but there do appear to be clear benefits both functionally and radiologically when considering patients of all ages.

CONCLUSION

Dynamic and static external fixators both achieve good outcomes for patients with unstable distal radius fractures with comparable complication rates. Non-bridging fixation may result in better functional and radiological results than static wrist-bridging fixation when considering patients of all ages with earlier return of function. This benefit does not seem apparent when considering older patients. Although a benefit was not seen in this group, the technique may have practical advantages over wrist-bridging fixation by allowing increased mobility and use of the limb during the fixation period and enabling such patients to maintain their independence. Cost effective analyses are required to assess whether this would be an economically viable option for this group of patients.

Cutaneous periocular Habronema infection in a dromedary camel (Camelus dromedarius)

A 6-year-old castrated dromedary camel (Camelus dromedarius) presented with a non-healing, severely pruritic, ulcerative fibrotic plaque located at the medial canthus. Histological examination of surgical biopsies identified degenerating nematode larvae within eosinophilic granulomas. Treatment involved repeated debridement of the lesion, injectable ivermectin and anti-inflammatory therapies, and injectable and topical antibiotics. A specially constructed mask with goggles to prevent the camel from continuing to self-traumatize the eye and lesion was also placed. Full recovery occurred approximately 1 month after diagnosis. Because of the location of the lesion, time of year, the gross and microscopic characteristics of the lesion, the presence of a likely nematode larva and the response to treatment, a diagnosis of cutaneous habronemiasis was made.

Relative preservation of MMSE scores in autopsy-proven dementia with Lewy bodies

BACKGROUND

Recent studies raised questions about the severity of cognitive impairment associated with dementia with Lewy bodies (DLB). However, there have been few analyses of large, multicenter data registries for clinical-pathologic correlation.

METHODS

We evaluated data from the National Alzheimer's Coordinating Center registry (n = 5,813 cases meeting initial inclusion criteria) and the University of Kentucky Alzheimer's Disease Center autopsy series (n = 527) to compare quantitatively the severity of cognitive impairment associated with DLB pathology vs Alzheimer disease (AD) and AD+DLB pathologies.

RESULTS

Mini-Mental State Examination (MMSE) scores showed that persons with pure DLB had cognitive impairment of relatively moderate severity (final MMSE score 15.6 +/- 8.7) compared to patients with pure AD and AD+DLB (final MMSE score 10.7 +/- 8.6 and 10.6 +/- 8.6). Persons with pure DLB pathology from both data sets had more years of formal education and were more likely to be male. Differences in final MMSE scores were significant (p < 0.01) between pure DLB and both AD+DLB and pure AD even after correction for education level, gender, and MMSE-death interval. Even in cases with extensive neocortical LBs, the degree of cognitive impairment was most strongly related to the amount of concomitant AD-type neurofibrillary pathology.

CONCLUSIONS

Dementia with Lewy bodies can constitute a debilitating disease with associated psychiatric, motoric, and autonomic dysfunction. However, neocortical Lewy bodies are not a substrate for severe global cognitive impairment as assessed by the Mini-Mental State Examination. Instead, neocortical Lewy bodies appear to constitute or reflect an additive disease process, requiring Alzheimer disease or other concomitant brain diseases to induce severe global cognitive deterioration.

The compressive behavior of the human glenoid labrum may explain the common patterns of SLAP lesions

PURPOSE

The aim of the study was to define the normalized compressive stiffness (modulus) of the glenoid labrum around its circumference and to characterize the difference in modulus between different areas.

METHODS

Sixteen fresh-frozen cadaveric shoulders were harvested and dissected down to the glenoid labrum. Any specimens with significant degenerative changes were discarded, leaving 8 labra for testing. The labrum was divided into 8 segments, to allow comparison around its circumference. A uniform testing specimen was produced from each area by use of a microtome. Each specimen measured 3 x 1 mm in cross section and was 6 mm in length. Indentation testing was conducted in a controlled environment of 100% humidity at 37 degrees C +/- 1 degrees C.

RESULTS

We obtained 52 test samples from 8 labra. The mean modulus of the glenoid labrum was 69.7 megapascal (standard deviation, 36.2 megapascal). The anterosuperior portion of the labrum had a higher modulus than the posteroinferior portion (P = .0075).

CONCLUSIONS

This study has shown that the human glenoid labrum's compressive behavior varies around its circumference. The greater modulus of the anterosuperior portion of the labrum supports the theory that this area is anatomically different from the rest of the labrum and resists compressive loads.

CLINICAL RELEVANCE

These results may explain why the common type of SLAP lesions seen show failure at the interface between the labrum and the glenoid rather than within the substance of the labrum itself.

Prodromal clinical manifestations of neuropathologically confirmed Lewy body disease

The mild cognitive impairment (MCI) stage of dementia with Lewy bodies (MCI-DLB) has not yet been defined, but is likely to differ in the MCI stage of Alzheimer's disease (MCI-AD). To determine whether clinical features distinguish MCI-DLB and MCI-AD, 9 cases of neuropathologically confirmed MCI-DLB and 12 cases of MCI-AD were compared. No significant differences were found between MCI-DLB and MCI-AD cases in age at death, gender, ApoE status, education, time followed while clinically normal, or duration of MCI. MCI-DLB and MCI-AD cases differed clinically in the expression of Parkinsonism (P=0.012), provoked hallucinations or delirium (P=0.042), or the presence of any of these noncognitive symptoms of DLB (P<0.0001). Letter fluency (P=0.007) was significantly lower and Wechsler Logical Memory I (P=0.019) was significantly higher in MCI-DLB compared to MCI-AD cases. These data demonstrate the feasibility of differentiating underlying pathologic processes responsible for cognitive decline in the preclinical disease state and suggest that further refinement in diagnostic criteria may allow more accurate early detection of prodromal DLB and AD.

Improved predictive model for pre-symptomatic mild cognitive impairment and Alzheimer's disease

OBJECTIVE

Delineation of gray matter (GM) structures on brain MRI scans is termed segmentation. Accuracy of segmentation is a key factor in the valid comparison of GM density and volume between individuals and groups. Previously, it was demonstrated that a group of normal subjects who later developed mild cognitive impairment (MCI) had decreased GM volume in the medial temporal lobe compared to other normal subjects who remained normal an average 5.4 years after the scan. The objective of this study was to show whether accuracy of this predictive model was increased using an advanced segmentation technique.

METHODS

Structural MRI was performed on 74 longitudinally examined normal aged subjects. All subjects were cognitively normal at the time of their scan, but 18 later developed MCI, and six of these 18 went on from MCI to an AD diagnosis. We independently delineated GM using both a standard segmentation technique and a local Gaussian active contour (LGAC) technique. We compared the contribution of extracted volumes from each technique to a model predicting subjects who will eventually develop MCI.

RESULTS

Accuracy of the standard technique to distinguish pre-MCI from normal using imaging alone was 79% (sensitivity 78% and specificity 73%). Using LGAC, accuracy rose to 84% (sensitivity 78% and specificity 84%).

DISCUSSION

Structural brain changes precede MCI in longitudinally followed normal subjects. The LGAC technique improves the accuracy of a predictive model incorporating these structural changes by improving GM segmentation and the specificity of the model.

Removal of embedded central venous catheters

BACKGROUND/PURPOSE

Long-term central venous access devices (CVAD) play an integral role in the management of children who require nutritional support, chemotherapy, blood drawing, and transfusion of blood products. Infrequently, the CVAD may be difficult or impossible to remove with traction.

PATIENT POPULATION

Four patients, with ages ranging from 6 to 13 years, had 4 CVAD in place for 431, 730, 2232, and 3285 days which could not be removed by manual traction and local exploration.

RESULTS

With the use of technology developed for removal of embedded transvenous pacemaker catheters, each CVAD was successfully dislodged using a lead locking device (n = 3) or a lead locking device and an excimer laser (n = 1). There were no complications of the procedure in our series.

CONCLUSIONS

There is no consensus on optimal management of embedded CVADs. In this small series, devices used routinely to remove embedded transvenous pacemaker wires were used to extract 4 embedded CVADs without complication; however, use of this technology in pediatric surgical patients is controversial because a small percentage of adult cases have resulted in tamponade or hemothorax, potentially resulting in death. Selection of patients and use of the technology in the appropriate setting are important considerations in weighing the risks vs the benefits of extracting such catheters or leaving them in place.

Collagenous microstructure of the glenoid labrum and biceps anchor

The glenoid labrum is a significant passive stabilizer of the shoulder joint. However, its microstructural form remains largely unappreciated, particularly in the context of its variety of functions. The focus of labral microscopy has often been histology and, as such, there is very little appreciation of collagen composition and arrangement of the labrum, and hence the micromechanics of the structure. On transmission electron microscopy, significant differences in diameter, area and perimeter were noted in the two gross histological groups of collagen fibril visualized; this suggests a heterogeneous collagenous composition with potentially distinct mechanical function. Scanning electron microscopy demonstrated three distinct zones of interest: a superficial mesh, a dense circumferential braided core potentially able to accommodate hoop stresses, and a loosely packed peri-core zone. Confocal microscopy revealed an articular surface fine fibrillar mesh potentially able to reduce surface friction, bundles of circumferential encapsulated fibres in the bulk of the tissue, and bone anchoring fibres at the osseous interface. Varying microstructure throughout the depth of the labrum suggests a role in accommodating different types of loading. An understanding of the labral microstructure can lead to development of hypotheses based upon an appreciation of this component of material property. This may aid an educated approach to surgical timing and repair.

Tensile properties of the human glenoid labrum

Human fresh-frozen cadaveric glenoid labrae from 16 donors were harvested and ten of these had no gross degeneration. These ten were divided into eight equal circumferential sections. Each section was cut to produce test-samples from the core layer with a cross-section of 1 x 1 mm. Tensile testing was performed within a controlled environment unit at 37 +/- 1 degrees C and 100% relative humidity. Each test-sample was precycled to a quasi-static state to alleviate the effects of deep-freezing, prior to final testing. The tangent modulus was calculated for each test-sample before and after a 5-min period of stress relaxation and at yield. The mean elastic modulus and yield stress of the glenoid labrum were 22.8 +/- 11.4 and 2.5 +/- 2.1 MPa, respectively. The anterosuperior portion had a lower elastic modulus and lower yield stress than the inferior portion (both P < 0.02). The pre-stress relaxation tangent modulus was significantly lower than the post-stress relaxation tangent modulus for all portions of the labrum. The glenoid labrum has similar tensile material properties to articular cartilage. Its elastic modulus varies around its circumference. This suggests that the labrum may encounter different forces at different positions.

Brain structural alterations before mild cognitive impairment

OBJECTIVE

To determine whether alterations of brain structure in normal aged individuals precede the development of mild cognitive impairment (MCI) or Alzheimer disease (AD).

BACKGROUND

Persons with MCI and AD demonstrate cortical volume losses vs asymptomatic aged individuals, particularly in the hippocampus, amygdala, and entorhinal cortex. It is unknown whether these losses or other volumetric changes are present, and to what degree, in cognitively normal individuals before the clinical diagnosis of MCI.

METHODS

Structural MRI was performed on a cross-section of 136 longitudinally examined normal aged subjects. All subjects were cognitively normal at the time of their scan, but 23 later developed MCI, and 9 of these 23 went on to an AD diagnosis. Extracted volumes from voxel-based morphometric analysis were combined with clinical data to compare the 23 subjects who eventually developed MCI to 113 subjects who remained cognitively normal over an average follow-up of 5.4 years.

RESULTS

Initially normal subjects who eventually developed MCI demonstrated decreased gray matter volumes in the anteromedial temporal lobes bilaterally and left angular gyrus while still cognitively normal.

CONCLUSION

Structural brain changes in anatomic areas involved in higher cognitive processes precede clinical signs and symptoms in longitudinally followed normal subjects destined to develop mild cognitive impairment.

Radiofrequency energy delivery to the lower esophageal sphincter (Stretta procedure) in patients with recurrent reflux after antireflux surgery: can surgery be avoided?

BACKGROUND

Recurrent reflux following antireflux surgery (ARS) can be difficult to manage, especially in patients who also fail medical management. In these patients, redo ARS remains the only treatment option. Endoscopic radiofrequency energy delivery to the lower esophageal sphincter (the Stretta procedure; Stretta, Curon, Sunnyvale, CA) has been shown to significantly decreased symptom scores and improve quality of life in patients with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the use of the Stretta procedure in treating patients with recurrent reflux after fundoplication.

METHODS

Between March 2002 and December 2003, eight patients with recurrent reflux following ARS underwent the Stretta procedure. All patients were asked to complete an institutional symptom survey pre-Stretta and at 1, 6, and 12 months after the procedure. Patients rated 7 reflux-related symptoms (heartburn, dysphagia, regurgitation, cough, voice changes/hoarseness, asthma, chest pain) on a 0 (none) to 3 (severe) scale. Data were analyzed using a Wilcoxon matched pairs signed rank test where appropriate.

RESULTS

Complete data were obtained for seven of the eight patients, with a median follow-up of 253 days (range, 67-378 days). One patient was lost to follow-up and not included in our analysis. Symptom scores decreased significantly, with six patients noting both improved typical and atypical symptoms. Overall, six patients (85%) were satisfied with their results.

CONCLUSIONS

Based on this small series, the Stretta procedure significantly reduces subjective symptoms of GERD. The Stretta procedure may serve an important role as an additional management strategy to help manage recurrent GERD after ARS.

The effect of escalating feedback on the acquisition of psychomotor skills for laparoscopy

BACKGROUND

In the acquisition of new skills that are difficult to master, such as those required for laparoscopy, feedback is a crucial component of the learning experience. Optimally, feedback should accurately reflect the task performance to be improved and be proximal to the training experience. In surgery, however, feedback typically is in vivo. The development of virtual reality training systems currently offers new training options. This study investigated the effect of feedback type and quality on laparoscopic skills acquisition.

METHODS

For this study, 32 laparoscopic novices were prospectively randomized into four training conditions, with 8 in each group. Group 1 (control) had no feedback. Group 2 (buzzer) had audio feedback when the edges were touched. Group 3 (voiced error) had an examiner voicing the word "error" each time the walls were touched. Group 4 (both) received both the audio buzzer and "error" voiced by the examiner All the subjects performed a maze-tracking task with a laparoscopic stylus inserted through a 5-mm port to simulate the fulcrum effect in minimally invasive surgery (MIS). A computer connected to the stylus scored an error each time the edge of the maze was touched, and the subjects were made aware of the error in the aforementioned manner. Ten 2-min trials were performed by the subjects while viewing a monitor. At the conclusion of training, all the subjects completed a 2-min trial of a simple laparoscopic cutting task, with the number of correct and incorrect incisions recorded.

RESULTS

Group 4 (both) made significantly more correct incisions than the other three groups (F = 12.13; df = 3, 28; p < 0.001), and also made significantly fewer errors or incorrect incisions (F = 14.4; p < 0.0001). Group 4 also made three times more correct incisions and 7.4 times fewer incorrect incisions than group 1 (control).

CONCLUSIONS

The type and quality of feedback during psychomotor skill acquisition for MIS have a large effect on the strength of skills generalization to a simple MIS task and should be given serious consideration in curriculum design for surgical training using simulation tasks.

Endoscopic ablation of intestinal metaplasia containing high-grade dysplasia in esophagectomy patients using a balloon-based ablation system

BACKGROUND

This study aimed to determine the optimal treatment parameters for the ablation of intestinal metaplasia (IM) containing high-grade dysplasia (HGD) using a balloon-based ablation system for patients undergoing esophagectomy.

METHODS

Immediately before esophagectomy, patients underwent ablation of circumferential segments of the esophagus containing IM-HGD using the HALO360 system. The treatment settings were randomized to 10, 12, or 14 J/cm2 for two, three, or four applications. After esophagectomy, multiple sections from ablation zones were microscopically evaluated. Histologic end points included maximum ablation depth (histologic layer) and complete ablation of all IM-HGD (yes/no).

RESULTS

Eight men with a mean age of 57 years (range, 45-71 years) were treated, and 10 treatment zones were created. There were no device-related adverse events. At resection, there was no evidence of a transmural thermal effect. Grossly, ablation zones were clearly demarcated sections of ablated epithelium. The maximum ablation depth was the lamina propria or muscularis mucosae. The highest energy (14 J/cm2, 4 applications) incurred edema in the superficial submucosa, but no submucosa ablation. Complete ablation of IM and HGD occurred in 9 of 10 ablation zones (90%), defined as complete removal of the epithelium with only small foci of "ghost cells" representing nonviable, ablated IM-HGD and demonstrating loss of nuclei and cytoarchitectural derangement. One focal area of viable IM-HGD remained at the margin of one ablation zone (12 J/cm2, 2 applications) because of incomplete overlap.

CONCLUSION

Complete ablation of IM-HGD without ablation of submucosa is possible using the HALO360 system. Ablation depth is dose related and limited to the muscularis mucosae. In one patient, small residual foci of IM-HGD at the edge of the ablation zone were attributable to incomplete overlap, which can be avoided. This study, together with nonesophagectomy IM-HGD trials currently underway, will identify the optimal treatment parameters for IM-HGD patients who would otherwise undergo esophagectomy or photodynamic therapy.

Attempted establishment of proficiency levels for laparoscopic performance on a national scale using simulation: the results from the 2004 SAGES Minimally Invasive Surgical Trainer—Virtual Reality (MIST-VR) learning center study

BACKGROUND

The Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) has been well validated as a training device for laparoscopic skills. It has been demonstrated that training to a level of proficiency on the simulator significantly improves operating room performance of laparoscopic cholecystectomy. The purpose of this project was to obtain a national standard of proficiency using the MIST-VR based on the performance of experienced laparoscopic surgeons.

METHODS

Surgeons attending the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) 2004 Annual Scientific Meeting who had performed more than 100 laparoscopic procedures volunteered to participate. All the subjects completed a demographic questionnaire assessing laparoscopic and MIST-VR experience in the learning center of the SAGES 2004 meeting. Each subject performed two consecutive trials of the MIST-VR Core Skills 1 program at the medium setting. Each trial involved six basic tasks of increasing difficulty: acquire place (AP), transfer place (TP), traversal (TV), withdrawal insert (WI), diathermy task (DT), and manipulate diathermy (MD). Trial 1 was considered a "warm-up," and trial 2 functioned as the test trial proper. Subject performance was scored for time, errors, and economy of instrument movement for each task, and a cumulative total score was calculated.

RESULTS

Trial 2 data are expressed as mean time in seconds in Table 2.

CONCLUSION

Proficiency levels for laparoscopic skills have now been established on a national scale by experienced laparoscopic surgeons using the MIST-VR simulator. Residency programs, training centers, and practicing surgeons can now use these data as guidelines for performance criterion during MIST-VR skills training.